Liquid crystal display device and manufacturing method thereof

ABSTRACT

A liquid crystal display according to the present inventive concept includes: a substrate; a gate line and a data line crossing each other formed on the substrate; a thin film transistor connected to the gate line and the data line; a pixel electrode connected to the thin film transistor and having a slit at a center; a liquid crystal layer filling a plurality of microcavities positioned on the pixel electrode; a common electrode positioned on the liquid crystal layer; and a roof layer formed on the common electrode and having an oblique portion formed to be inclined at both outer sides of the microcavities.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2014-0136004 filed in the Korean IntellectualProperty Office on Oct. 8, 2014, the entire contents of which areincorporated herein by reference.

BACKGROUND

(a) Field

The present inventive concept relates to a liquid crystal display and amanufacturing method thereof. More particularly, the present inventiveconcept relates to a display device with improved transmittance and amanufacturing method thereof.

(b) Description of the Related Art

A liquid crystal display (hereinafter referred to as an LCD) is one ofthe most widely used flat panel displays. The LCD includes two displaypanels provided with electric field generating electrodes, such as pixelelectrodes and a common electrode, and a liquid crystal layer interposedbetween the two display panels. In the LCD, voltages are applied to theelectric field generating electrode to generate an electric field in theliquid crystal layer. Due to the generated electric field, liquidcrystal molecules of the liquid crystal layer are aligned andpolarization of incident light is controlled, thereby displaying images.

The two display panels forming the liquid crystal display may be a thinfilm transistor array panel and an opposing display panel. In the thinfilm transistor array panel, a gate line transmitting a gate signal anda data line transmitting a data signal are formed to be crossed, and athin film transistor connected to the gate line and the data line and apixel electrode connected to the thin film transistor may be formed. Theopposing display panel may include a light blocking member, a colorfilter, a common electrode, etc. If necessary, the light blockingmember, the color filter, and the common electrode may be formed in thethin film transistor array panel.

However, in the conventional liquid crystal display, two substrates areinevitably required, and the constituent elements are respectivelyformed on the two substrates such that the display device is heavy, thecost is high, and the processing time is long.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the inventive conceptand therefore it may contain information that does not form the priorart.

SUMMARY

The present inventive concept relates to a display device with reducedweight, thickness, cost, and processing time by manufacturing thedisplay device by using one substrate, and a manufacturing methodthereof.

Also, a display device with improved luminance and a manufacturingmethod thereof are provided.

A liquid crystal display according to an exemplary embodiment of thepresent inventive concept includes: a substrate; a gate line and a dataline crossing each other formed on the substrate; a thin film transistorconnected to the gate line and the data line; a pixel electrodeconnected to the thin film transistor and having a slit at a center; aliquid crystal layer filling a plurality of microcavities positioned onthe pixel electrode; a common electrode positioned on the liquid crystallayer; and a roof layer formed on the common electrode and having anoblique portion formed to be inclined at both outer sides of themicrocavities.

An oblique angle of the oblique portion may be formed in a range of 10degrees to 80 degrees.

A width of the slit may be formed of a range of about 1 to about 11 μm.

The width of the slit may be formed of a range of about 5 μm to about 9μm.

The oblique portion may be formed to cover right and left sides of themicrocavities.

The common electrode may be formed of a plate shape parallel to the gateline to cover the right and left sides of the microcavities.

The pixel electrode may include a first electrode and a second electrodepositioned at a right side and a left side with respect to the slit.

The first electrode and second electrode may extend in a direction inwhich the data line extends.

The first electrode and the second electrode may be connected to eachother.

The first electrode and the second electrode may be formed to beconnected at one side or both sides of the pixel electrode.

The pixel electrode may include a first electrode and a second electroderespectively positioned at a left side and a right side with respect tothe slit, and the first and second electrodes may include a first regionextending in a direction from a lower left toward an upper right and asecond region extending in a direction from an upper left toward a lowerright.

A manufacturing method of a liquid crystal display according to anexemplary embodiment of the present inventive concept includes: forminga thin film transistor on a substrate; forming a pixel electrodeconnected to the thin film transistor and including a slit at a center;forming a sacrificial layer on the pixel electrode; forming a commonelectrode on the sacrificial layer; forming a roof layer including anoblique portion formed to be inclined at both sides outside themicrocavities on the common electrode; patterning the roof layer toexpose a portion of the sacrificial layer to form a liquid crystalinjection hole; removing the sacrificial layer to form microcavitiesbetween the pixel electrode and the common electrode; injecting a liquidcrystal material into the microcavities through the liquid crystalinjection hole to form a liquid crystal layer; and forming an overcoatroof layer to seal the microcavities.

The oblique portion may be formed to have an oblique angle of about 10degrees to about 80 degrees.

The width of the slit may be formed in a range of about 1 μm to about 11μm.

The width of the slit may be formed of a range of about 5 μm to about 9μm.

The oblique portion may be formed to cover a right side and a left sideof the microcavities.

The common electrode may be formed of one plate shape to cover the rightside and the left side of the microcavities.

The pixel electrode may include a first electrode and a second electroderespectively positioned at a right side and a left side with respect tothe slit.

The first electrode and second electrode may be connected to each other.

The first electrode and second electrode may be connected to each otherat one side or both sides of the pixel electrode.

In addition to the technical object of the present inventive concept,other characteristics and advantages of the present inventive conceptwill be described hereinafter, and will be clearly understood by aperson skilled in the art in the technical field to which the presentinventive concept belongs.

The present inventive concept provides subsequent advantages.

According to the exemplary embodiments of the present inventive concept,it is possible to reduce weight, thickness, cost, and processing time bymanufacturing the display device by using one substrate.

Also, luminance may be improved by controlling the inclination angle ofthe oblique portion included in the roof layer and the width of the slitincluded in the pixel electrode.

Further, the viewing angle may be improved by forming the sub-pixel ofthe 4-domain structure.

In addition, other characteristics and advantages of the presentinventive concept can be found through the exemplary embodiments of thepresent inventive concept.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a liquid crystal display according to anexemplary embodiment of the present inventive concept.

FIG. 2 is an equivalent circuit diagram of one pixel of a liquid crystaldisplay according to an exemplary embodiment of the present inventiveconcept.

FIG. 3A and FIG. 3B are layout views of one pixel of a liquid crystaldisplay according to an exemplary embodiment of the present inventiveconcept.

FIG. 4 is a cross-sectional view of one pixel of a liquid crystaldisplay according to an exemplary embodiment of the present inventiveconcept of FIG. 3A taken along a line IV-IV.

FIG. 5 is a cross-sectional view of one pixel of a liquid crystaldisplay according to an exemplary embodiment of the present inventiveconcept of FIG. 3A taken along a line V-V.

FIG. 6 is a perspective view of a basic form of a field generatingelectrode of a liquid crystal display according to an exemplaryembodiment of the present inventive concept.

FIG. 7 is a cross-sectional view of a basic region of a field generatingelectrode of a liquid crystal display according to an exemplaryembodiment of the present inventive concept of FIG. 6 taken along a lineVII-VII.

FIG. 8 is a view showing a configuration of a liquid crystal whenapplying an electric field to a field generating electrode of a liquidcrystal display according to an exemplary embodiment of the presentinventive concept.

FIG. 9A and FIG. 9B are views showing a transmittance characteristicaccording to a slit interval of a liquid crystal display according to anexemplary embodiment of the present inventive concept.

FIG. 10A, FIG. 10B, FIG. 10C, and FIG. 10D are views showing atransmittance characteristic according to an oblique angle of an obliqueportion of a liquid crystal display according to an exemplary embodimentof the present inventive concept.

FIG. 11 is a plane view of a sub-pixel of a liquid crystal displayaccording to an exemplary embodiment of the present inventive concept.

FIG. 12 is a cross-sectional view of a sub-pixel of the liquid crystaldisplay of FIG. 11 taken along a line XII-XII.

FIGS. 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,29, 30, 31 and 32 are process cross-sectional views of a manufacturingmethod of a liquid crystal display according to an exemplary embodimentof the present inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present inventive concept will be described more fully hereinafterwith reference to the accompanying drawings, in which exemplaryembodiments of the inventive concept are shown. As those skilled in theart would realize, the described embodiments may be modified in variousdifferent ways, all without departing from the spirit or scope of thepresent inventive concept.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening elements may also be present between the element and theother element. In contrast, when an element is referred to as being“directly on” another element, there are no intervening elements presentbetween the element and the other element.

Firstly, a liquid crystal display according to an exemplary embodimentof the present inventive concept will be described with reference toFIG. 1.

FIG. 1 is a top plan view of a liquid crystal display according to anexemplary embodiment of the present inventive concept.

A liquid crystal display according to an exemplary embodiment of thepresent inventive concept includes a substrate 110 made of a materialsuch as glass or plastic.

The substrate 110 includes a plurality of pixel areas PXs. The pluralityof pixel areas PXs are disposed in a matrix form which includes aplurality of pixel rows and a plurality of pixel columns. Each pixelarea PX may include a first sub-pixel area PXa and a second sub-pixelarea PXb. The first sub-pixel area PXa and the second sub-pixel area PXbmay be vertically disposed.

Microcavities 305 covered by roof layers 360 are formed on the substrate110. The roof layer 360 is connected in a row direction, and one rooflayer 360 may form a plurality of microcavities 305.

A first valley V1 is positioned between the first and second subpixelareas PXa and PXb along a pixel row direction, and a second valley V2 ispositioned between a plurality of pixel columns.

The plurality of roof layers 360 may be separated from each other withthe first valley V1 interposed therebetween. The microcavities 305 maynot be covered by the roof layer 360, but may be exposed to the outsideat portions corresponding to the first valley V1. The exposed areas arereferred to as injection holes 307.

Each roof layer 360 is separated from the substrate 110 between theadjacent second valleys V2 to form the microcavity 305. Further, eachroof layer 360 is attached to the substrate 110 at the second valley V2to cover both sides of the microcavity 305.

A structure of the display device according to the exemplary embodimentof the present inventive concept described above is just exemplified andmay be variously modified. For example, a layout form of the pixel areaPX, the first valley V1, and the second valley V2 may be changed, andthe plurality of roof layers 360 may be connected to each other at thefirst valley V1, and a part of each roof layer 360 may be separated fromthe substrate 110 at the second valley V2 and thus the adjacentmicrocavities 305 may be connected to each other.

Next, one pixel of the display device according to the exemplaryembodiment of the present inventive concept will be briefly describedbelow with reference to FIGS. 2 and 3.

FIG. 2 is an equivalent circuit diagram of one pixel of the displaydevice according to the exemplary embodiment of the present inventiveconcept, FIG. 3A and FIG. 3B are layout views illustrating one pixel ofthe display device according to the exemplary embodiment of the presentinventive concept. FIG. 3A and FIG. 3B are the same except for aconnected portion of the first electrode and the second electrode of theliquid crystal display according to an exemplary embodiment of thepresent inventive concept.

The display device according to the exemplary embodiment of the presentinventive concept includes signal lines such as a gate line 121, astorage electrode line 125, a step-down gate line 123, and a data line171.

A first switching element Qh, a second switching element Ql, a thirdswitching element Qc, a first liquid crystal capacitor Clch, a secondliquid crystal capacitor Clcl, a first storage capacitor Csth, a secondstorage capacitor Cstl, and a step-down capacitor Cstd are connected tothe signal lines. Hereinafter, the first switching element Qh and thefirst thin film transistor Qh, the second switching element Ql and thesecond thin film transistor Ql, and the third switching element Qc andthe third thin film transistor Qc are represented by the same referencenumerals, respectively.

The first and second switching elements Qh and QI are connected to thegate line 121 and the data line 171, respectively, and the thirdswitching element Qc is connected to the step-down gate line 123.

The first and second switching elements Qh and Ql are three-terminalelements such as a thin film transistor formed on the substrate 110, andcontrol terminals thereof are connected to the gate line 121, inputterminals thereof are connected to the data line 171, and outputterminals thereof are connected to the first and second liquid crystalcapacitors Clch and Clcl and the first and second storage capacitorsCsth and Cstl, respectively.

The third switching element Qc is also a three-terminal element such asa thin film transistor formed on the substrate 110, and a controlterminal thereof is connected to the step-down gate line 123, an inputterminal thereof is connected to the second liquid crystal capacitorClcl, and an output terminal thereof is connected to the step-downcapacitor Cstd.

The first and second liquid crystal capacitors Clch and Clcl are formedby overlapping first and second subpixel electrodes 191 h and 191 lconnected with the first and second switching elements Qh and Q with acommon electrode 270. The first and second subpixel electrodes 191 h and191 l are formed below the microcavity 305, and the common electrode 270is formed on the microcavity 305. The first and second storagecapacitors Csth and Cstl are formed by overlapping the storage electrodeline 125 with the first and second subpixel electrodes 191 h and 191 l.

The step-down capacitor Cstd is connected to the output terminal of thethird switching element Qc and the storage electrode line 125, and isformed so that the storage electrode line 125 and the output terminal ofthe third switching element Qc are overlapped with an insulatortherebetween.

Now, a driving method of the display device illustrated in FIGS. 2 and 3will be described.

When a gate-on signal is applied to the gate line 121, the firstswitching element Qh and the second switching element Ql which areconnected to the gate line 121 are turned on. As a result, the datavoltage applied to the data line 171 is applied to the first subpixelelectrode 191 h and the second subpixel electrode 191 l through theturned-on first switching element Qh and second switching element Ql. Inthis case, magnitudes of the data voltages applied to the first subpixelelectrode 191 h and the second subpixel electrode 191 l are the same.Accordingly, the voltages charged in the first and second liquid crystalcapacitors Clch and Clcl are also the same.

Thereafter, when a gate-off signal is applied to the gate line 121 andthe gate-on signal is applied to the step-down gate line 123, the firstswitching element Qh and the second switching element Ql are turned offand the third switching element Qc is turned on. Then, charges move tothe step-down capacitor Cstd from the second subpixel electrode 191 lthrough the third switching element Qc. Subsequently, the chargedvoltage of the second liquid crystal capacitor Clcl is decreased, andthe step-down capacitor Cstd is charged. Since the charged voltage ofthe second liquid crystal capacitor Clcl is decreased by capacitance ofthe step-down capacitor Cstd, the charged voltage of the second liquidcrystal capacitor Clcl is lower than the charged voltage of the firstliquid crystal capacitor Clch.

In this case, the charged voltages of the two liquid crystal capacitorsClch and Clcl represent different gamma curves, and a gamma curve of onepixel voltage becomes a curve acquired by combining the different gammacurves. A combined gamma curve at the front coincides with a referencegamma curve at the front which is most appropriately determined, and acombined gamma curve at the side becomes closest to the reference gammacurve at the front. As such, side visibility may be improved byconverting image data.

FIG. 4 is a cross-sectional view of one pixel of a liquid crystaldisplay according to an exemplary embodiment of the present inventiveconcept of FIG. 3A taken along a line IV-IV, and FIG. 5 is across-sectional view of one pixel of a liquid crystal display accordingto an exemplary embodiment of the present inventive concept of FIG. 3Ataken along a line V-V.

As illustrated in FIG. 3A, FIG. 3B, FIG. 4, and FIG. 5, the displaydevice according to the exemplary embodiment of the present inventiveconcept includes a gate conductor formed on the insulation substrate 110and including the gate line 121, the step-down gate line 123, thestorage electrode line 125, and the like.

The gate line 121 and the step-down gate line 123 mainly extend in ahorizontal direction to transfer gate signals. The gate line 121includes a first gate electrode 124 h and a second gate electrode 124 lprotruding upward and downward, and the step-down gate line 123 includesa third gate electrode 124 c protruding upward. The first gate electrode124 h and the second gate electrode 124 l are connected with each otherto form one protrusion. However, shapes of the protrusions which formsthe first, second, and third gate electrodes 124 h, 124 l, and 124 c maybe changed.

The storage electrode line 125 also mainly extends in a horizontaldirection to transfer a predetermined voltage such as common voltageVcom. The storage electrode line 125 includes a capacitor electrode 126which protrudes upward and downward to surround an edge of the pixelarea, and, particularly, includes a capacitor electrode 126 which isexpanded downward.

A gate insulating layer 140 is formed on the gate conductors 121, 123,and 125. The gate insulating layer 140 may be made of an inorganicinsulating material such as a silicon nitride (SiNx) and a silicon oxide(SiOx). Further, the gate insulating layer 140 may be constituted by asingle layer or a multi-layer.

A first semiconductor 154 h, a second semiconductor 154 l, and a thirdsemiconductor 154 c are formed on the gate insulating layer 140. Thefirst semiconductor 154 h may be positioned on the first gate electrode124 h, the second semiconductor 154 l may be positioned on the secondgate electrode 124 l, and the third semiconductor 154 c may bepositioned on the third gate electrode 124 c. The first semiconductor154 h and the second semiconductor 154 l may be connected to each other,and the second semiconductor 154 l and the third semiconductor 154 c maybe connected to each other. Further, the first semiconductor 154 h mayextend below the data line 171. The first to third semiconductors 154 h,154 l, and 154 c may be made of amorphous silicon, polycrystallinesilicon, a metal oxide semiconductor, and the like.

Ohmic contacts (not illustrated) may be further formed on the first tothird semiconductors 154 h, 154 l, and 154 c, respectively.

A data conductor including the data line 171, a first source electrode173 h, a second source electrode 173 l, a third source electrode 173 c,a first drain electrode 175 h, a second drain electrode 175 l, and athird drain electrode 175 c is formed on the first to thirdsemiconductors 154 h, 154 l, and 154 c.

The data line 171 transfers a data signal and mainly extends in avertical direction to cross the gate line 121 and the step-down gateline 123.

The first source electrode 173 h protruding from the data line 171 isformed on the first gate electrode 124 h, and the second sourceelectrode 173 l is formed on the second gate electrode 124 l. The firstsource electrode 173 h and the second source electrode 173 l areconnected to each other to receive the same data signal from the dataline 171.

The first drain electrode 175 h, the second drain electrode 175 l, andthe third drain electrode 175 c include one wide end portion and theother rod-shaped end portion, respectively. The rod-shaped end portionsof the first drain electrode 175 h and the second drain electrode 175 lare partially surrounded by the first source electrode 173 h and thesecond source electrode 173 l, respectively. One wide end portion of thesecond drain electrode 175 l again extends to form a third sourceelectrode 173 c which is bent in a ‘U’-shape. A wide end portion 177 cof the third drain electrode 175 c is overlapped with the capacitorelectrode 126 to form the step-down capacitor Cstd, and the rod-shapedend portion is partially surrounded by the third source electrode 173 c.

The first/second/third gate electrodes 124 h/124 l/124 c, thefirst/second/third source electrodes 173 h/173 l/173 c, and thefirst/second/third drain electrodes 175 h/175 l/175 c formfirst/second/third thin film transistors (TFTs) Qh/Ql/Qc together withthe first/second/third semiconductors 154 h/154 l/154 c, respectively,and channels of the thin film transistors are formed in the respectivesemiconductors 154 h/154 l/154 c between the respective sourceelectrodes 173 h/173 l/173 c and the respective drain electrodes 175h/175 l/175 c.

A passivation layer 180 is formed on the data conductors 171, 173 h, 173l, 173 c, 175 h, 175 l, and 175 c and the semiconductors 154 h, 154 l,and 154 c exposed between the respective source electrodes 173 h/173l/173 c and the respective drain electrodes 175 h/175 l/175 c. Thepassivation layer 180 may be made of an organic insulating material oran inorganic insulating material, and may be formed as a single layer ora multi-layer.

A color filter 230 in each pixel area PX is formed on the passivationlayer 180. Each color filter 230 may display one of primary colors suchas three primary colors of red, green, and blue. The color filter 230 isnot limited to the three primary colors of red, green, and blue, but maydisplay cyan, magenta, yellow, and white-based colors. Unlike asillustrated above, the color filter 230 may be elongated in a columndirection along a space between the adjacent data lines 171.

A light blocking member 220 is formed in a region between adjacent colorfilters 230. The light blocking member 220 is formed on a boundary ofthe pixel area PX and the thin film transistor to prevent light leakage.That is, the light blocking member 220 may be formed at the first valleyV1 and the second valley V2. The color filter 230 and the light blockingmember 220 may partially overlap with each other.

A first insulating layer 240 may be further formed on the color filter230 and the light blocking member 220. The first insulating layer 240may be made of an inorganic insulating material such as a siliconnitride (SiNx) and a silicon oxide (SiOx). The first insulating layer240 serves to protect the color filter 230 and the light blocking member220 which are made of the organic materials, and may be omitted ifnecessary.

A plurality of first contact holes 185 h and a plurality of secondcontact holes 185 l which expose the wide end portion of the first drainelectrode 175 h and the wide end portion of the second drain electrode175 l, respectively, are formed in the first insulating layer 240, thelight blocking member 220, and the passivation layer 180.

A pixel electrode 191 is formed on the first insulating layer 240. Thepixel electrode 191 includes a slit S formed at a center of the pixelelectrode 191. In this case, a width of the slit S may be formed of arange of 1 to 11 μm.

That is, the pixel electrode 191 includes the first sub-pixel electrode191 h and the second sub-pixel electrode 191 l, and the first and secondsub-pixel electrodes 191 h/191 l include a first electrode 191 a and asecond electrode 191 b that are respectively at a right side and a leftside with respect to the slit S. The first electrode 191 a and thesecond electrode 191 b may be respectively formed of a plate shape atthe left side and the right side with the respect to the slit S. In thiscase, as shown in FIG. 3A, the first electrode 191 a and the secondelectrode 191 b may be formed to be connected at one side outside theslit S, and in another exemplary embodiment, as shown in FIG. 3B, thefirst electrode 191 a and the second electrode 191 b may be formed to beconnected at both sides outside the slit S.

In the liquid crystal display according to an exemplary embodiment ofthe present inventive concept, by forming the slit S at the center ofthe pixel electrode 191, the transmittance deterioration due to abreakage phenomenon of the liquid crystal alignment layer may beprevented in the center portion of the pixel area. This will bedescribed in detail later. The pixel electrode 191 may be formed of thetransparent metal material such as indium-tin oxide (ITO), indium-zincoxide (IZO).

The pixel electrode 191 includes the first sub-pixel electrode 191 h andthe second sub-pixel electrode 191 l that are separated from each otheron the gate line 121 and the step-down gate line 123. The firstsub-pixel electrode 191 h and the second sub-pixel electrode 191 l aredisposed on and below the gate line 121 and the step-down gate line 123,and neighbor each other in a column direction. That is, the firstsubpixel electrode 191 h and the second subpixel electrode 191 l areseparated from each other with the first valley V1 therebetween, thefirst subpixel electrode 191 h is positioned in the first subpixel areaPXa, and the second subpixel electrode 191 l is positioned in the secondsubpixel area PXb.

The first sub-pixel electrode 191 h and the second sub-pixel electrode191 l are connected to the first drain electrode 175 h and the seconddrain electrode 175 l through the first contact hole 185 h and thesecond contact hole 185 l, respectively. Accordingly, when the firstthin film transistor Qh and the second thin film transistor Ql are theON state, the data voltage is applied from the first drain electrode 175h and the second drain electrode 175 l.

The common electrode 270 is formed on the pixel electrode 191 to beseparate from the pixel electrode 191 by a predetermined distance. Themicrocavities 305 are formed between the pixel electrode 191 and thecommon electrode 270. The width and the area of the microcavities 305may be variously changed according to the resolution of the displaydevice.

The common electrode 270 may be made of the transparent metal materialsuch as ITO and IZO. A constant voltage may be applied to the commonelectrode 270, and an electric field may be formed between the pixelelectrode 191 and the common electrode 270.

Here, the common electrode 270 may be formed of plate shape electrodesparallel to the gate line 121 to cover an upper side, a right side and aleft side of the microcavities 305, and a connection portion connectingthe adjacent plate shape common electrodes with each other.

A liquid crystal layer including liquid crystal molecules 310 is formedin the microcavity 305 positioned between the pixel electrode 191 andthe common electrode 270. The liquid crystal molecules 310 have negativedielectric anisotropy, and may arranged in a vertical direction withrespect to the substrate 110 while the electric field is not applied.That is, the liquid crystal molecules 310 are vertical alignment typeliquid crystal molecules.

A first alignment layer 11 is formed on the pixel electrode 191. Thefirst alignment layer 11 may be formed even on the first insulatinglayer 240 that is not covered by the pixel electrode 191.

A second alignment layer 21 is formed below the common electrode 270 toface the first alignment layer 11.

The first alignment layer 11 and the second alignment layer 21 mayinclude a vertical alignment layer, and may be made of a material suchas polyamic acid, polysiloxane, polyimide, and the like. The first andthe second alignment layers 11 and 21 may be may be formed through asame process step and be connected to each other at the edge of thepixel area PX.

The first sub-pixel electrode 191 h and the second sub-pixel electrode191 l to which the data voltage is applied generate the electric fieldtogether with the common electrode 270 to thereby determine anorientation of liquid crystal molecule 310 positioned within themicro-cavity 305 formed between the pixel electrode 191 and the commonelectrode 270. Luminance of light passing through the liquid crystallayer varies based on the orientation of liquid crystal molecules 310which is determined by the data voltage applied to the first sub-pixelelectrode 191 h and the second sub-pixel electrode 191 l.

The first subpixel electrode 191 h and the common electrode 270 form afirst liquid crystal capacitor Clch together with the liquid crystallayer therebetween, and the second subpixel electrode 191 l and thecommon electrode 270 form a second liquid crystal capacitor Clcltogether with the liquid crystal layer therebetween. As a result, evenafter the first and second thin film transistors Qh and Ql are turnedoff, the applied voltage is maintained by the first liquid crystalcapacitor Clch and the second liquid crystal capacitor Clcl.

The first and second subpixel electrodes 191 h and 191 l overlap withthe storage electrode line 125 to form the first and second storagecapacitors Csth and Cstl, and the first and second storage capacitorsCsth and Cstl maintain the voltage between the first and second subpixelelectrodes 191 h and 191 l, and the common electrode 270.

The capacitor electrode 126 and a wide end portion 177 c of the thirddrain electrode 175 c overlap with each other with the gate insulatinglayer 140 therebetween to form the step-down capacitor Cstd.

As describe above, the first subpixel electrode 191 h and the secondsubpixel electrode 191 l to which the data voltages are applied generatethe electric field together with the common electrode 270, and as aresult, the liquid crystal molecules 310 of the liquid crystal layerwhich are aligned so as to be vertical with respect to the surfaces ofthe two electrodes 191 and 270 while the electric field is not appliedare tilted in a direction parallel to the surfaces of the two electrodes191 and 270 and luminance of light passing through the liquid crystallayer varies according to the tilted degree of the liquid crystalmolecules 310.

The microcavities 305 are enclosed by the pixel electrode 191 and thecommon electrode 270.

The common electrode 270 is formed to be connected directly on the firstinsulating layer 240 at the second valley V2 and thus the commonelectrode 270 may be formed to cover a left side and a right side of themicrocavity 305. That is, the common electrodes 270 are connected toeach other along the plurality of pixel rows, and a height of the commonelectrode 270 positioned at the second valley V2 is smaller than aheight of the common electrode positioned in the pixel area PX. Thereason is that the microcavities 305 are not formed below the commonelectrode 270 positioned at the second valley V2.

The common electrode 270 is not formed on at least a partial region ofthe first valley V1. That is, the common electrode 270 is formed so asnot to cover at least a part of the upper side and the lower side of thepixel area PX and thus a part of the microcavity 305 is exposed outside.The side where the microcavity 305 is exposed is called a liquid crystalinjection hole 307. The liquid crystal injection holes 307 are formed atone edge of the microcavities 305 of the direction parallel to the dataline 171 according to the first valley V1, and the liquid crystalmaterial is injected inside the microcavities 305 through the liquidcrystal injection hole 307.

In the above, the common electrode 270 covers the left surface and theright surface of the microcavities 305 and does not cover at least aportion of the upper surface and the lower surface of the microcavities305, but the present inventive concept is not limited thereto, and thecommon electrode 270 may be formed to cover other surfaces of themicrocavities 305. For example, the common electrode 270 may cover theupper surface and the lower surface of the microcavities 305 and atleast a portion of the left surface and the right surface thereof maynot be covered. In this case, the liquid crystal injection hole 307 maybe formed along the second valley V2.

The roof layer 360 is formed on the common electrode 270. The roof layer360 may be made of an organic material. The microcavity 305 is formedbelow the roof layer 360, and a shape of the microcavity 305 may bemaintained by the roof layer 360.

The roof layers 360 are connected to each other along the plurality ofpixel rows like the common electrode 270, and the liquid crystalinjection hole 307 is formed along the first valley V1 in the roof layer360 and thus a part of the microcavity 305 is exposed outside.

The roof layer 360 includes an oblique portion E as disclosed in FIGS. 7and 8 that is formed to be inclined at both sides of the microcavities305.

The oblique portion E is formed to cover both outer sides of themicrocavities 305 and may have an oblique angle of about 10 degrees toabout 80 degrees.

A second insulating layer 370 may be formed on the roof layer 360. Thesecond insulating layer 370 may be made of an inorganic insulatingmaterial such as a silicon nitride (SiNx) and a silicon oxide (SiOx).The second insulating layer 370 may be formed to cover the upper sideand the both sides of the roof layer 360. The second insulating layer370 serves to protect the roof layer 360 made of an organic material,and may be omitted if necessary.

An overcoat 390 may be formed on the second insulating layer 370. Theovercoat 390 is formed to cover the liquid crystal injection hole 307where a part of the microcavity 305 is exposed to outside.

That is, the overcoat 390 may seal the microcavity 305 so that theliquid crystal molecules 310 formed in the microcavity 305 are notdischarged to outside of the microcavity 305. Since the overcoat 390contacts the liquid crystal molecules 310, the overcoat 390 may be madeof a material which does not react with the liquid crystal molecules310. For example, the overcoat 390 may be made of parylene and the like.

The overcoat 390 may be formed of a multilayer such as a double layerand a triple layer. The double layer is configured by two layers made ofdifferent materials. The triple layer is configured by three layers, andmaterials of adjacent layers are different from each other. For example,the overcoat 390 may include a layer made of an organic insulatingmaterial and a layer made of an inorganic insulating material.

Although not illustrated, polarizers may be further formed on the upperand lower sides of the display device. The polarizers may be configuredby a first polarizer and a second polarizer. The first polarizer isattached onto the lower side of the substrate 110, and the secondpolarizer may be attached onto the overcoat 390.

Hereinafter, a basic form of the field generating electrode of thedisplay device according to the exemplary embodiment of the presentinventive concept will be described with reference to FIG. 6 to FIG. 8.

FIG. 6 is a perspective view of a basic form of a field generatingelectrode of a liquid crystal display according to an exemplaryembodiment of the present inventive concept, FIG. 7 is a cross-sectionalview of a field generating electrode of a liquid crystal displayaccording to an exemplary embodiment of the present inventive concept,and FIG. 8 is a view showing a configuration of a liquid crystal whenapplying an electric field to a field generating electrode of a liquidcrystal display according to an exemplary embodiment of the presentinventive concept.

Firstly, referring to FIG. 6 and FIG. 7, the field generating electrodeincludes the common electrode 270 of the plate shape disposed on themicrocavities 305 and the pixel electrode 191 disposed under themicrocavities 305 and including the slit S in the center.

The pixel electrode 191 includes the first electrode 191 a and thesecond electrode 191 b positioned at the right side and the left sidewith respect to the slit S. The first electrode 191 a and the secondelectrode 191 b extend in the direction parallel to the data line (notshown) and are respectively formed of one plate shape at the right sideand the left side with respect to the slit S. In this case, the width Wof the slit S may be formed with the range of 1 to 11 μm.

The roof layer 360 is positioned on the common electrode 270. The rooflayer 360 may be formed to cover the microcavities 305, and includes theoblique portion E formed to be inclined at both sides of themicrocavities 305. In this case, the oblique angle of the obliqueportion E may be formed of the range of 10 degrees to 80 degrees withrespect to the roof layer 360.

The liquid crystal molecules initially aligned to be vertical withrespect to walls of the microcavities 305 are inclined toward thedirection parallel to the surface of two electrodes 191 and 270 by theelectric field formed by the pixel electrode 191 and the commonelectrode 270.

In this case, when the vertically arranged liquid crystal molecules arerearranged through the electric field, the liquid crystal moleculesshould be aligned with continuity. However, when using the non-patternedcommon electrode 270 and the pixel electrode 191, the continuity of theliquid crystal molecules at the center of the pixel area is destroyedsuch that the transmittance of the pixel at the center is reduced.

In the liquid crystal display according to an exemplary embodiment ofthe present inventive concept, by forming the pixel electrode 191including the slit S at the center of the pixel area, the transmittancedeterioration due to the discontinuity of the liquid crystal at thecenter of the pixel area is thereby prevented.

Referring to FIG. 8, in the liquid crystal display according to anexemplary embodiment of the present inventive concept, when applying theelectric field to the liquid crystal molecules 305 using the commonelectrode 270 having the oblique portion E, the oblique portion E maygive directionality to the liquid crystal molecules 310, and therearrangement of the liquid crystal molecules starts at the edges of themicrocavity 305 and progresses to the center of the pixel area in whichslit S of the pixel electrode 191 exists, such that the liquid crystalmolecules may be arranged with continuity even at the center part of thepixel area.

FIG. 9A and FIG. 9B are views showing a transmittance characteristicaccording to a width of the slit of a liquid crystal display accordingto an exemplary embodiment of the present inventive concept when theinclination angle of the oblique portion E included in the roof layer isfixed at 50 degrees while the width of the slit included in the pixelelectrode is changed.

Referring to FIG. 9A and FIG. 9B, the liquid crystal display accordingto an exemplary embodiment of the present inventive concept includes theslit S positioned at the center of the pixel area, and the firstelectrode 191 a and the second electrode 191 b positioned at the rightside and the left side of the slit S.

In this case, the width of the slit S may be formed in the range ofabout 1 to about 11 μm. When the width of the slit S is in the rage ofabout 5 μm to about 9 μm the transmittance of the pixel is improvedgreatly. When the width of the slit S is 7 μm, the transmittance isbest.

FIG. 10A to FIG. 10D are views showing a transmittance characteristicaccording to an oblique angle of an oblique portion of a liquid crystaldisplay according to an exemplary embodiment of the present inventiveconcept, and are simulation views for measuring the transmittance in acondition that the width of the slit included in the pixel electrode isfixed at 7 μm while changing the angle that the oblique portion includedin the roof layer is inclined.

Referring to FIG. 10A to FIG. 10D, in the liquid crystal displayaccording to an exemplary embodiment of the present inventive concept,the roof layer 360 is formed on the microcavities 305 in which theliquid crystal molecules 310 are positioned, and the roof layer 360includes the oblique portion E that is inclined at the both outer edgesof the microcavities 305.

The inclination angle of the oblique portion E may be variously formedfrom about 10 degrees to about 80 degrees, and the oblique portion E ofthe roof layer 360 may be included with the predetermined angle suchthat the rearrangement of the liquid crystal molecules starts at theedges of the microcavity 305 and progresses to the center of the pixelarea in which slit S of the pixel electrode 191 exists.

That is, the liquid crystal display according to an exemplary embodimentof the present inventive concept controls the inclination angle of theoblique portion E included in the roof layer 360 and the width W of theslit S included in the pixel electrode 191, thereby improving theluminance.

Next, the sub-pixel of the liquid crystal display according to anexemplary embodiment of the present inventive concept with the improvedviewing angle will be described with reference to FIG. 11 and FIG. 12.

FIG. 11 is a plan view of a sub-pixel of a liquid crystal displayaccording to an exemplary embodiment of the present inventive concept,and FIG. 12 is a cross-sectional view of a sub-pixel of the liquidcrystal display of FIG. 11 taken along a line XII-XII.

Referring to FIG. 11 and FIG. 12, one sub-pixel of the liquid crystaldisplay according to an exemplary embodiment of the present inventiveconcept may be formed with a 4-domain structure.

One sub-pixel of the liquid crystal display according to the presentinventive concept includes the common electrode 270 having the plateshape and disposed on the microcavities 305, and the pixel electrode 191including the slit S and disposed under the microcavities 305.

The pixel electrode 191 includes the first electrode 191 a and thesecond electrode 191 b positioned on a right side and a left side of theslit S.

The first and second electrodes 191 a and 191 b are divided into firstand second domain regions inclined by +45 degrees with respect to thecenter line, and third and fourth domain regions inclined by −45 degreeswith respect to the center line.

That is, the first electrode 191 a includes the first domain region D1inclined by +45 degrees with respect to the center line thereby beingslanted from the lower left toward the upper right and the third domainregion D3 inclined by −45 degrees with respect to the center linethereby being slanted from the upper left toward the lower right, andthe second electrode 191 b includes the second domain region D2 inclinedby +45 degrees with respect to the center line thereby being slantedfrom the lower left toward the upper right and the fourth domain regionD4 inclined by −45 degrees with respect to the center line thereby beingslanted from the upper left toward the lower right.

In the pixel structure including the above-described 2-domain region,when applying the electric field, the liquid crystal molecules 310 areinclined with right and left symmetry with respect to the slit S suchthat the viewing angle is compensated in the right and left directions,that is, the lateral directions, however the viewing angle of thevertical direction is not compensated. However, one sub-pixel of theliquid crystal display according to an exemplary embodiment of thepresent inventive concept includes the 4 domain regions such that thedirection of the liquid crystal molecules 310 is not only divided rightand left, but is also divided up and down with respect to the slit S,thereby improving the viewing angle in the vertical direction as well asthe lateral direction.

Next, a manufacturing method of the liquid crystal display according toan exemplary embodiment of the present inventive concept will bedescribed with reference to FIG. 13 to FIG. 32. Furthermore, FIG. 1 toFIG. 5 will be described together therewith.

First, referring to FIG. 13 and FIG. 14, a gate line 121 and a step-downgate line 123 extending in one direction are formed on a substrate 110made of glass or plastic, and a first gate electrode 124 h, a secondgate electrode 124 l, and a third gate electrode 124 c which protrudefrom the gate line 121 are formed on the substrate 110.

Further, the storage electrode line 125 may be formed together therewithso as to be spaced apart from the gate line 121, the step-down gate line123, and the first to third gate electrodes 124 h, 124 l, and 124 c.

Next, a gate insulating layer 140 is formed on the entire surface of thesubstrate 110 including the gate line 121, the step-down gate line 123,the first to third gate electrodes 124 h, 124 l, and 124 c, and thestorage electrode line 125 by using an inorganic insulating materialsuch as a silicon oxide (SiOx) or a silicon nitride (SiNx). The gateinsulating layer 140 may be formed of a single layer or a multi-layer.

Next, a first semiconductor 154 h, a second semiconductor 154 l, and athird semiconductor 154 c are formed on the gate insulating layer 140 bydepositing a semiconductor material such as amorphous silicon,polycrystalline silicon, and a metal oxide semiconductor and thenpatterning the deposited semiconductor material. The first semiconductor154 h may be disposed on the first gate electrode 124 h, the secondsemiconductor 154 l may be disposed on the second gate electrode 124 l,and the third semiconductor 154 c may be disposed on the third gateelectrode 124 c.

As illustrated in FIG. 15 and FIG. 13, a data line 171 extending in theother direction is formed by depositing a metallic material and thenpatterning the deposited metallic material. The metallic material may beformed of a single layer or a multi-layer.

Further, a first source electrode 173 h protruding above the first gateelectrode 124 h from the data line 171 and a first drain electrode 175 hspaced apart from the first source electrode 173 h are formed together.Further, a second source electrode 173 l connected with the first sourceelectrode 173 h and a second drain electrode 175 l spaced apart from thesecond source electrode 173 l are formed together. Further, a thirdsource electrode 173 c extends from the second drain electrode 175 l anda third drain electrode 175 c spaced apart from the third sourceelectrode 173 c are formed together.

The first to third semiconductors 154 h, 154 l, and 154 c, the data line171, the first to third source electrodes 173 h, 173 l, and 173 c, andthe first to third drain electrodes 175 h, 175 l, and 175 c may beformed by sequentially depositing the semiconductor material and themetallic material and then patterning the semiconductor material and themetallic material at the same time. In this case, the firstsemiconductor 154 h may extend to the lower portion of the data line171.

The first/second/third gate electrodes 124 h/124 l/124 c, thefirst/second/third source electrodes 173 h/173 l/173 c, and thefirst/second/third drain electrodes 175 h/175 l/175 c formfirst/second/third thin film transistors (TFTs) Qh/Ql/Qc together withthe first/second/third semiconductors 154 h/154 l/154 c, respectively.

As illustrated in FIG. 17 and FIG. 18, a passivation layer 180 is formedon the data line 171, the first to third source electrodes 173 h, 173 l,and 173 c, the first to third drain electrodes 175 h, 175 l and 175 c,and the semiconductors 154 h, 154 l, and 154 c exposed between therespective source electrodes 173 h/173 l/173 c and the respective drainelectrodes 175 h/175 l/175 c. The passivation layer 180 may be made ofan organic insulating material or an inorganic insulating material, andmay be formed of a single layer or a multi-layer.

Next, a color filter 230 is formed in each pixel area PX on thepassivation layer 180. The color filters 230 having the same color maybe formed in a column direction of the plurality of pixel areas PXs. Inthe case of forming the color filters 230 having three colors, a firstcolored color filter 230 may be first formed and then a second coloredcolor filter 230 may be formed by shifting a mask. After forming thesecond colored color filter 230, a third colored color filter may beformed by shifting the mask.

Next, a light blocking member 220 is formed on a boundary of each pixelarea PX on the passivation layer 180 and the thin film transistor.

Hereinabove, the light blocking member 220 is formed after forming thecolor filters 230, but the present inventive concept is not limitedthereto, and the light blocking member 220 may be first formed and thenthe color filters may be formed.

Next, a first insulating layer 240 made of an inorganic insulatingmaterial such as a silicon nitride (SiNx) and a silicon oxide (SiOx) isformed on the color filter 230 and the light blocking member 220.

Next, by etching the passivation layer 180, the light blocking member220, and the first insulating layer 240, a first contact hole 185 h isformed so as to expose a part of the first drain electrode 175 h, and asecond contact hole 185 l is formed so as to expose a part of the seconddrain electrode 175 l.

As shown in FIG. 19 and FIG. 20, a first subpixel electrode 191 h isformed in a first subpixel area PXa and a second subpixel electrode 191l is formed in a second subpixel area PXb by depositing and patterning atransparent metal material such as indium tin oxide (ITO) and indiumzinc oxide (IZO) on the first insulating layer 240. The first subpixelelectrode 191 h is connected with the first drain electrode 175 hthrough the first contact hole 185 h, and the second subpixel electrode191 l is connected with the second drain electrode 175 l through thesecond contact hole 185 l.

Also, the slit S is respectively formed at the first sub-pixel electrode191 h and the second sub-pixel electrode 191 l.

The slit S is formed in the direction parallel to the data line 171 atthe center of the first sub-pixel electrode 191 h and the secondsub-pixel electrode 191 l. The slit S may have zigzag shape as alreadydescribed above with respect to FIG. 11. At this time, the width W ofthe slit S may be formed with the range of about 1 μm to about 11 μm.

That is, the first sub-pixel electrode 191 h and the second sub-pixelelectrode 191 l may respectively include the first electrode 191 a andthe second electrode 191 b at the right side and left side with respectto the slit S.

As illustrated in FIG. 21 and FIG. 22, a sacrificial layer 300 is formedby coating a photosensitive organic material on the pixel electrode 191and through a photolithography process. The sacrificial layer 300 may bemade of a positive photosensitive material.

The sacrificial layers 300 are formed to be connected along a pluralityof pixel columns. That is, the sacrificial layer 300 is formed to covereach pixel area PX and to cover the first valley V1 positioned betweenthe first subpixel area PXa and the second subpixel area PXb.

In this case, edges of the sacrificial layer 300 may be formed to beinclined in the predetermined angle with respect to the first insulatinglayer 240.

As illustrated in FIG. 23 and FIG. 24, a common electrode 270 is formedby depositing a transparent metal material such as indium tin oxide(ITO) and indium zinc oxide (IZO) on the sacrificial layer 300.

The common electrode 270 is substantially formed to cover each pixelarea PX and to cover the second valley V2 positioned between theadjacent pixel areas PXs.

In this case, the common electrode 270 may be formed of plate shapeelectrodes parallel to the gate line 121 to cover an upper side, a rightside and a left side of the microcavities 305, and a connection portionconnecting the adjacent plate shape common electrodes with each other.

As shown in FIG. 25 and FIG. 26, the roof layer 360 made of the organicmaterial is formed on the common electrode 270.

The roof layer 360 may be patterned to remove the roof layer 360positioned on the first valley V1.

In this case, the roof layer 360 forms the oblique portion E inclinedwith the predetermined angle at the outside positioned at the secondvalley V2. The oblique angle of the oblique portion E may be formed withthe range of about 10 degrees to about 80 degrees.

As shown in FIG. 27 and FIG. 28, the second insulating layer 370 made ofthe inorganic insulating material such as a silicon nitride (SiNx) or asilicon oxide (SiOx) may be formed on the roof layer 360. The secondinsulating layer 370 is formed on the patterned roof layer 360, therebycovering and protecting the side of the roof layer 360, that is, theoblique portion E.

As shown in FIG. 29 and FIG. 30, the second insulating layer 370 ispatterned to remove the second insulating layer 370 positioned on thefirst valley V1.

The second insulating layer 370 is patterned such that the sacrificiallayer 300 positioned at the first valley V1 is exposed.

The sacrificial layer 300 is fully removed by supplying a strippersolution on the substrate 110 where the sacrificial layer 300 isexposed, or the sacrificial layer 300 is fully removed by an ashingprocess. If the sacrificial layer 300 is removed, the microcavities 305are generated at the position in which the sacrificial layer 300 ispositioned.

The pixel electrode 191 and the common electrode 270 are spaced apartfrom each other with the microcavity 305 interposed therebetween, andthe pixel electrode 191 and the roof layer 360 are spaced apart fromeach other with the microcavity 305 interposed therebetween. The commonelectrode 270 and the roof layer 360 are formed to cover the upper sideand both sides of the microcavity 360.

Further, the microcavity 360 is exposed outside through a portion wherethe roof layer 360 and the common electrode 270 are removed, which iscalled the liquid crystal injection hole 307. The liquid crystalinjection hole 307 is formed along the first valley V1.

Next, the roof layer 360 is cured by applying heat to the substrate 110.The shape of the microcavity 305 is maintained by the roof layer 360.

Next, when an aligning agent containing an alignment material is formedon the substrate 110 by a spin coating method or an inkjet method, thealigning agent is injected into the microcavity 305 through the liquidcrystal injection hole 307. When the aligning agent is injected into themicrocavity 305 and then a curing process is performed, a solution inthe aligning agent is evaporated and the alignment material remains onthe inner wall of the microcavity 305.

Accordingly, the first alignment layer 11 may be formed on the pixelelectrode 191, and the second alignment layer 21 may be formed below thecommon electrode 270. The first alignment layer 11 and the secondalignment layer 21 face each other with the microcavity 305 therebetweenand are connected to each other at the edge of the pixel area PX.

In this case, the first and second alignment layers 11 and 21 may bealigned in a vertical direction with respect to the substrate 110 exceptat the side of the microcavity 305. In addition, a process ofirradiating UV light to the first and second alignment layers 11 and 21may be performed to align the first and second alignment layers 11 and21 in a horizontal direction with respect to the substrate 110.

Next, when the liquid crystal material including the liquid crystalmolecules 310 is formed on the substrate 110 by an inkjet method or adispensing method, the liquid crystal material is injected into themicrocavity 305 through the liquid crystal injection hole 307. In thiscase, the liquid crystal material may be provided in the liquid crystalinjection holes 307 formed along the odd-numbered first valleys V1 butmay not be provided in the liquid crystal injection holes 307 formedalong the even-numbered first valleys V1. On the contrary, the liquidcrystal material may be provided in the liquid crystal injection holes307 formed along the even-numbered first valleys V1 but may not beprovided in the liquid crystal injection holes 307 formed along theodd-numbered first valleys V1.

When the liquid crystal material is formed in the liquid crystalinjection hole 307 formed along the odd-numbered first valleys V1, theliquid crystal material is injected into the micro cavities 306 from theliquid crystal injection holes 307 by capillary force. In this case, theliquid crystal material is injected into the microcavities 305 well bydischarging air from the microcavities 305 through the liquid crystalinjection holes 307 formed along the even-numbered first valleys V1.

Further, the liquid crystal material may be dropped in all the liquidcrystal injection holes 307. That is, the liquid crystal material may beformed in the liquid crystal injection holes 307 formed along theodd-numbered first valleys V1 and the liquid crystal injection holes 307formed along the even-numbered first valleys V1.

As illustrated in FIG. 31 and FIG. 32, an overcoat layer 390 is formedby forming a material which does not react with the liquid crystalmolecules 310 on the second insulating layer 370. The overcoat 390 isformed to cover the liquid crystal injection holes 307 where themicrocavity 305 is exposed outside to seal the microcavities 305.

Next, although not illustrated, polarizers may be further attached ontothe upper and lower sides of the display device. The polarizers may beconfigured by a first polarizer and a second polarizer. The firstpolarizer may be attached onto the lower side of the substrate 110, andthe second polarizer may be attached onto the overcoat 390.

While this inventive concept has been described in connection with whatis presently considered to be practical exemplary embodiments, it is tobe understood that the inventive concept is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A liquid crystal display comprising: a substrate;a gate line and a data line crossing each other formed on the substrate;a thin film transistor connected to the gate line and the data line; apixel electrode connected to the thin film transistor and having a slitat a center; a liquid crystal layer filling a plurality of microcavitiespositioned on the pixel electrode; a common electrode positioned on theliquid crystal layer; and a roof layer formed on the common electrodeand having an oblique portion formed to be inclined at both sides of themicrocavities.
 2. The liquid crystal display of claim 1, wherein anoblique angle of the oblique portion is formed in a range of about 10degrees to about 80 degrees.
 3. The liquid crystal display of claim 1,wherein a width of the slit is formed of a range of about 1 μm to about11 μm.
 4. The liquid crystal display of claim 1, wherein a width of theslit is formed of a range of about 5 μm to about 9 μm.
 5. The liquidcrystal display of claim 1, wherein the oblique portion is formed tocover right and left sides of the microcavities.
 6. The liquid crystaldisplay of claim 5, wherein the common electrode is formed of a plateshape parallel to the gate line to cover the right and left sides of themicrocavities.
 7. The liquid crystal display of claim 1, wherein thepixel electrode includes a first electrode and a second electrodepositioned at a right side and a left side with respect to the slit. 8.The liquid crystal display of claim 7, wherein the first electrode andsecond electrode extend in a direction in which the data line extends.9. The liquid crystal display of claim 7, wherein the first electrodeand the second electrode are connected to each other.
 10. The liquidcrystal display of claim 9, wherein the first electrode and the secondelectrode are formed to be connected at one side or both sides of thepixel electrode.
 11. The liquid crystal display of claim 1, wherein thepixel electrode includes a first electrode and a second electroderespectively positioned at a left side and a right side with respect tothe slit, and the first and second electrodes include a first regionextending in a direction from a lower left toward an upper right and asecond region extending in a direction from an upper left toward a lowerright.
 12. A method for manufacturing a liquid crystal display,comprising: forming a thin film transistor on a substrate; forming apixel electrode connected to the thin film transistor and including aslit at a center; forming a sacrificial layer on the pixel electrode;forming a common electrode on the sacrificial layer; forming a rooflayer including an oblique portion formed to be inclined at both sidesoutside the microcavities on the common electrode; patterning the rooflayer to expose a portion of the sacrificial layer to form a liquidcrystal injection hole; removing the sacrificial layer to formmicrocavities between the pixel electrode and the common electrode;injecting a liquid crystal material into the microcavities through theliquid crystal injection hole to form a liquid crystal layer; andforming an overcoat roof layer to seal the microcavities.
 13. The methodof claim 12, wherein the oblique portion is formed to have an obliqueangle of about 10 degrees to about 80 degrees.
 14. The method of claim12, wherein the width of the slit is formed in a range of about 1 μm toabout 11 μm.
 15. The liquid crystal display of claim 12, wherein a widthof the slit is formed of a range of about 5 μm to about 9 μm.
 16. Themethod of claim 12, wherein the oblique portion is formed to cover aright side and a left side of the microcavities.
 17. The method of claim16, wherein the common electrode is formed of one plate shape to coverthe right side and the left side of the microcavities.
 18. The method ofclaim 12, wherein the pixel electrode includes a first electrode and asecond electrode respectively positioned at a right side and a left sidewith respect to the slit.
 19. The method of claim 18, wherein the firstelectrode and second electrode are connected to each other.
 20. Themethod of claim 19, wherein the first electrode and second electrode areconnected to each other at one side or both sides of the pixelelectrode.